Wheel-dressing device for grinding machines



A ril 29, 1930. F. JUDGE E AL WHEEL DRE S SING DEVICE FOR GRINDING MAbHINES FiledMarch 19, 1925 4 Sheets-Sheet 1 +22%; 11, /7i&/7 Jg 177]] a.

April 29, 1930. F JUDGE ET AL WHEEL DRESSING DEVICE FOR GRINDING MACHINES 1925 4 Sheets-Sheet i--- LLi an A .MMHM@.IL

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. WHEEL DRESSING-DEVICE FOR GRINDING MACHINES Filed March 19, 1925 4 Sheets-Sheet 3 WHEEL DRESSING DEVICE FOR GRINDING MACHINES Filed March 19, 1925 4 Sheefcs-Sheet 4 April 29, 1930. F. JU-DGE ET AL 1,756,646

- Patented Apr. 29, 1930 UNITED STATES PATENT OFFICE FRANKLIN JUDGE AND ALDEN M. DRAKE, O'F GREENFIELD, MASSACHUSETTS, AS- SIGNORS TO GREENFIELD TAP & DIE CORPORATION, OF GREENFIELD, MASSACHU- SETTS, A CORPORATION OF MASSACHUSETTS WHEEL-DRESSING DEVICE FOR GRINDING MACHINES Application filed March 19, 1925. Serial No. 16,759.

This invention relates to a Wheel dressing device and to mechanism for controlling and positioning the same and is particularly designed for use with internal grinding machines. Certain features of the invention, however, are capable of more general application and are not limited in their utility to a particular type of machine.

In the operation of grinding machines,

particularly of the internal type, it 1s desirable to dress the wheel between the roughing and the finishing cuts and it is also desirable to remove the wheel dressing tool from operative position while the work and wheel are movedapart to permit gauging or replacement of the work.

It is the general object of our invention to provide means by which the wheel may be thus dressed or trimmed after the roughing out is completed, and particularly to provide means for withdrawing the tool from operative position as the wheel and finished work are thereafter separated.

A further object of our invention is to so co-ordinate the movements of the wheel dressing tool with the movements of the operating handle that the tool will be automatically retracted from working position upon movement of the handle to the position for high speed separation of the wheel and work.

Our invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings in which Fig. 1 is a partial front elevation of an internal grinding machine embodying our improvements;

Fig. 2 is an enlarged front elevation of the table controlling mechanism:

Fig. 3 is a partial sectional side elevation, taken along the line 3-3 in Fig. 2;

Fig. 4 is a partial plan view, looking in the direction of the arrow 4 in Fig. 2;

Fig. 5 is a detail plan view of certain parts to be described;

Fig. 6 is a plan view of a portion of the grin ing machine, including the wheel dressing device and the mechanism for controlling the position thereof;

Fig. 7 is a sectional side elevation, taken tions looking in the directions of the arrows i 12, 13 and 14 in Figs. 9, 10 and 11 and correspondin to the in said figures.

We will first describe briefly the general type of internal grinding machine to which we have shown our invention applied. The grinding machine shown in the drawings comprises a base 20 provided with a sliding table 21 which supports a head or bearing 22 for a work spindle 23. The work K may be held in a suitable chuck 24 mounted on the spindle 23 and may be rotated in any convenient manner as by a belt 25 and driving drum 26.

A grinding wheel W is rotatably mounted positions of the parts shown in a wheel head 27 supported on the base 20' and preferably permitting the table 21 to slide thereunder. The machine illustrated is provided with hydraulic table actuating mechanism of the type shown in the prior application of Ralph H. Morgan, Serial No. 425,475, filed Nov. 20, 1920, and the table is governed in its movement by controlling mechanism of the type shown'in the copending application of Alden M. Drake, Serial No. 13,602. filed Mar. 6, 1925.

Briefly described, this table actuating and controlling mechanism comprises a main valve mounted in a valve casing 28 and having a valve rod '29 to which a hand lever 30 is pivoted. The lever 30 swings about the axis of a speed control valve 32 by which the flow of liquid to the hydraulic table operating mechanism may be varied. When the lever 30 is pulled forward, the valve 32 is opened and the rate of movement of the table is increased. The lever 30 may also be swung to the. right or the left, changing the setting of the main valve and thus stopping or reversin the table travel at any desired point.

The main valve is also controlled by an auxiliary valve having a valve stem 33 enaged by a stop screw 34 when the table :21 is travelling to the right. The valve stem 33 is also provided with two plates 35 and 36 which are angularl-y positioned by a rod 37 positioned in notches in said plates and mounted on-a member 380 which moves angularly about the axis of the valve rod 29 as the handle 30 is swung outward.

When the handle is in normal position, a stop dog 38 on the table 21 engages the plate 35 and moves the auxiliary valve to reverse the table travel. When the work is to be withdrawn from the wheel a shortdistance to permit dressing of the wheel, the handle 30 is swung outward an amount sufficient to cause the plate 35 to clear the dog 38 but permitting the'dog 38 to engage the plate 36. The increased amount of travel of the table is thus determined by' the spacing of the plates 35 and 36.

When the handle 30 is moved still further forward, both plates 35 and 36 are moved out of the path of the dog 38 and the table continues its travel toward the left until a stop dog 40 engages the handle 30 and moves the same to mid-position, bringing the table to rest.

When the table is thus moved to the left beyond the position determined by the dog 38, a cam bar 41 (Figs. 4 and 5) engages a roll 46 and presses the same outward against a fiat rear surface on the lever 30, maintaining the lever in outward position during the further travel of the table to the left and causing this further travel to take place at high speed. The mechanism above described is more fully disclosed in the prior applications above cited and in itself forms no part of our present invention, which relates to improved wheel dressing devices and to mechanism for positioning the same.

In order that the purpose of our invention may be clearly understood, attention is called to the diagrammatic views, Figs. 9 to 14 inclusive.

In Figs. 9 and 12 the grinding wheel W is shown as entering a piece of work K, which is indicated as having the form of a hollow cylinder or ring. A diamond tool '45 is mounted on the table which supports the work K and is normally positioned in the line b, which indicates the size of the hole when the roughing out has been completed. The relative position of the parts at the end of the roughing cut is indicated in Figs. 10 and13. At this point it is desirable to move the work K and the tool relatively to the wheel W by an amount of extra travel suflicient'to carry the dressing tool across the face'of the wheel. This is accomplished, as previously described, by moving the handle 30 forward sufliciently so that the plate 35 will clear the dog 38. v

The grinding Wheel then completes the finish cut by removing the few ten-thousandths of an inch left by the roughing cut, bringing the hole to the exact finished size. The wheel and work are then separated by pulling the handle 30 forward enough to cause both plates 35. and 36 to clear the dog 38, moving the table 21 at higher speed to the extreme left to permit gauging of the work and removal and replacement thereof.

During this latter separation of the wheel and work it is not desired to dress the wheel, as there is no reason for dressing the wheel again until after the next roughing cut has been completed. But, in order to facilitate the removal of the work from the chuck, which is on the same carriage with the tool 45, it is desirable to separate the tool and the chuck, through a'transverse tiltin of the tool. Accordingly the tool 45 shou d be removed from the path of the wheel as indicated in Figs. 11 and 14.

lVe will now describe the mechanism by which we normally position the Wheel dressing tool 45 and by which we withdraw it from normal position, when the table and work are moved to the left at the completion of the finish cut. The diamond point or wheel dressing tool 45 is mounted for longitudinal adjustment in a support 50 (Fig. 7) pivoted at 51 on a stand 52 adjustable longitudinally on the table 21. 'A stop screw 53 engages a shoulder 54 on the support 50 and is positioned for engagement by fixed cam plates 56 and 57 and by a movable cam plate 58 (Fig. 6). The cam plate 58 is above the cam roll and is held in raised position when the wheel is in engagement with the" work by a spring 59 (Fig. 6). The upward movement of the plate is limitedv by a stop screw 60 (Fig. 7) engaging the stand 61 on which the plate 58 is pivoted, the screw being adjustable so that theplate 58 will justclear the roll 55' when the shoulder 54 engages the stop screw 53.

The plate 58 is connected by a cord or other connecting member 62 (Fig. 7) to the hand lever 30, the cord passing around one or more suitable guide pulleys 63. The cord 62 is adjusted with a certain amount of slack, so

that a movement of the handle 30 which will cause the plate 35 to clear the dog 38 will merely take up the slack and will not depress the plate 58. The tool 45 thus remains in operative position for dressing the wheel after the roughing cut.

'Further movement of the handle to the outward position in which the dog 38 clears both plates 35 and 36 simultaneously depresses the plate 58, moving the tool 45 from the positions shown in Figs. 12 and 13 to the position indicated in full lines in Fig. 14 in which position the tool 45 cannot engage the til the parts return to normal working relation.

We have thus provided means permitting the wheel dressing tool to remain in operative position during limited separation of the wheel and Work for dressing the wheel but automatically removing the dressing tool from operative position upon further separation of the Wheel and work, such as that which takes place after the cut is completed and when the parts are to be changed. Furthermore this removal of the dressing tool from operative position is accomplished without any personal attention from the operator and does not depend in any way upon his conscious action.

Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but what we claim is 1. In a grinding machine, a. work holder, a grinding wheel, a wheel dressing tool positioned when operative, in proximity to said holder, means to axially separate the wheel and work for dressing the wheel, and toeifect a greater axial separation of thejwheel and work for removing the work, and mechanism rendered operative by such increased axial separation to automatically swing said dress: ing tool about an axis parallel to the axis of rotation of said wheel and away from said axis and from operative position during said movement of increased separation.

2. In a grinding machine, a work holder, a grinding wheel, a wheel dressing tool positioned when operative, in proximity to said holder, means to move the dressing tool relatively to the wheel to dress the wheel at one machine speed, and to effect relative axial separation of the tool and wheel at greater speed, and mechanism effective to automatically and simultaneously swing the tool about an axis parallel to the axis of rotation of said wheel and away from said axis and from operative position as the wheel and tool are thus axially separated at increased speed.

3. In a grinding machine, a work holder, a grinding wheel, a wheel dressing tool positioned when operative, in proximity to said holder, means to cause relative movement of the dressing tool past the wheel to dress the wheel at one 'machine speed, and to relatively move the tool a greater distance past the wheel at an increased speed, and mechanism rendered operative by such increased separation and effective to automatically and simult'ancously swing the tool about an axis parallel to the axis of rotation of said wheel and away from said axis and from operative position.

4. In a grinding machine, a work holder, a grinding wheel,'a Wheel dressing tool positioned, when operative, in proximity to said holder, and a single controlling device effective in one position to cause relative movement of the dressing tool pastthe wheel to dress the Wheel, and effective in a different position to cause greater movement of the tool past the wheel and to withdraw the tool from operative position.

5. The combination in a grinding machine as set forth in claim 4, in which the controlling device effects the greater movement at an increased speed.

6. In a grinding machine, a work holder, a grinding wheel, a wheel dressing tool positioned when operative, in proximity to said holder, and controlling means to cause relative axial separation of the work and wheel to permit removal of the work, and means to automatically and simultaneously swing the dressing tool about an axis parallel to the axis of rotation of said wheel and away from said axis and from operative position, the said latter means being rendered operative by such axial movement of separation of the wheel and work.

7. In a grinding machine, a work holder, a rinding wheel, a wheel dressing tool sitioned when operative, in proximity to said holder, and controlling means to cause relative axial separation of the work and wheel to permit removal of the work, means to automatically and simultaneously swing the dressing tool about an axis parallel to the axis of rotation of said wheel and away from said axis and from operative position, the said latter means being rendered operative by such axial movement of separation of the wheel and work, and a lost motion connection between said controlling means and said 9. In a grinding machine, a wheel dressing tool, a cam plate capable of being swung into contact with the tool, and manual means to move said plate to withdraw said tool from operative position.

10. In a grinding machine, a wheel dressing tool, a cam plate capable of being, swung into contact with the tool,.manual means to move said plate to withdraw said tool from o erative position, and an additional cam ate effective to withdraw said dressing tool 5 urther from operative position.

11. In a grinding machine, a frame, a grinding wheel, a table, a wheel dressing tool mounted on said table, fixed and movable cam plates mounted on said frame, said movable plate being capable of swin ing into contact with the tool, and means to epress said movable cam plate to withdraw said tool from operative position, said tool being thereafter further withdrawn by said fixed cam' plate.

12. In a grinding machine, a work holder, a wheel, a wheel dressing tool positioned, when 0 era'tive, in proximity to said holder, a hand ever effective in one position tocause relative travel of said tool past said wheel to 2o dress the wheel, and efiective in another position to cause relative travel of greater extent to permit replacement of the work, and

' to simultaneously displace said tool transversely to the wheel axis from operative po- 28 sition. 3

In testimony whereof we have hereunto aflixed our signatures.

FRANKLIN JUDGE. ALDEN M. DRAKE. 

